Recently, my TB started spitting fuel into the airbox. Only noticed it when I found a slow drip of fuel from the corner of the airbox when the bike was leaned over on the sidestand.
I checked it out with RPM here in Dallas and they diagnosed worn o-rings in the float chambers allowing fuel to leak past. They sold me some suitable o-rings and ordered the float bowl gaskets.
I started the bike with the petcock closed and used up the fuel in the line and the carbs. Then pulled the tank, horn, side covers and carbs (see tip at bottom). Inverted the carbs, undid the two allen bolts holding each float bowl, pulled out each float assembly, replaced the two o-rings, cleaned out the float bowls, replaced the gaskets and re-assembled. Not too difficult - less than one hours work.
Remounted everything and went for a ride. Bike was running well for about 60/70 miles with a couple of stops and then, as I headed for home, she gave a bit of a splutter. Checked the trip and yes, she needed to switch to reserve. She went onto two cylinders and stayed like that to the gas station. She did this once before and I figured it was just the carb furthest from the fuel line not getting enough becuase I was slow switching over. But even when I filled up, she stayed on two cylinders. OK at idle but above 2000 revs, nbr one would just cut out.
Because she'd run so well, I figured I had a new, separate problem to the job I'd done. I was thinking fuel starvation due to sucking up some gunge as the tank got low, so I checked and cleaned the inline fuel filter between carb two and three. No go. Then drained the tank, removed the petcock, found loads of cr*p, disassembled it, cleaned it and even got a tube into the tank and sucked up any loose bits. Still no go. Sh*t - pull the carbs again!
Since nbr one was the bad 'un, I opened the float chamber on that first and checked my work. Everything looked kosher and was a good fit. So, baffled, I was about to reassemble when something caught my eye. Something in the needle jet? Unscrewed it and held up to the light and yes - definitely something. I winkled it out using a pin (VERY GENTLY) and it was the tiniest, tiniest piece of blue roll. In other words, my EFFING fault for using a linty cloth to clean the float bowls in the first place. B*llocks!
It must have lying in the bottom, and got sucked up when the fuel got low, and was just big enough to jam but not big enough to block completely. Anyhow, just to be sure, I checked the other two chambers for lintiness and put it all back together again.
Bike is running well now, haven't seen any fuel from the airbox, but I'll keep an eye on that one.
USEFUL TIP. Screw one side cover mounting bolt into each side of the airbox - only part way though. Now use those screws as mounting points for a long bungee cord. Loop the bungee over something at the back, like the seat mount or the tail light, so that the airbox is pulled to it's rearmost position and
stays there. Now you can use both hands to manhandle the carbs in or out.
Cheers
